Comparator



D156 29, 1936. l s B TERRY 2,065,951

COMPARATOR Filed March 26, 19255A INVENoR.

. //ATT0R y I Patented Dec. 29, 1936 by mesne assignments, toNiles-Bement-Pond Company, New York, N. Y., a corporation of New JerseyApplication Mai-chas, 1935, serial No. 13,113

2 Claims.

This invention relates to a dimension gage or comparator and moreparticularly to a precision gage for comparing the dimensions of sizeblocks such as the well-known Johansson or Hoke fblocks with standardsofr known precision.

for simultaneously determining the relative dimensions of two gageblocks, each block being mounted on the base of the gage and beingindivvidually in contact with oneof the spaced apart gaging contacts ofa pivotally mounted member, the relative size of the blocks beingindicated by va suitable electric indicating instrument associated withand indicating the tilted position of the pivotally mounted member. Afeature which enables me to accomplish the above named object is thatthe pivotally mounted contacting member referred'to above is provided inan adjustably mountedgaging head; the pivotally mounted member havingtwo anvils or contacts laterally spaced apart on opposite sides of thepivotal mounting so that the pivotal member will be tilted to differentpositions by different sizes of blocks mounted on the base and inengagement individually with these contacts.-

Another object of .the invention is to lprovide lextreme precision meansfor indicating lthe different tilted positions of. 'a pivotally mountedcontact member when.the two contacts thereon 30 are engaged by the gagesor articles being compared.

A further-object of the invention is to provide means permitting alimited movement of the entire head in which the pivotally mounted co'n-'35 tacting' member is provided so that slightly different positions-ofthe head may be assumed toward or from the base on which the. articlesbeing compared are mounted, these movements not interfering with theprecision of the gaging or W comparingoperations.

' With the above and other objects in view my invention includes thefeatures' of construction 'and operation set forth in the followingspeciflcation and illustrated inthe accompanying y 45 drawing.

In the accompanying drawing annexed hereto and forming a part oi' thisspecification, I have shown my invention embodied in a bench type gageor comparator ofextreme precision having 50 an adjustable bracket toaccommodate articles of different dimensions, but it will be understoodthat the invention' can be otherwise embodied and that the drawing isnot to be construed as denning or limiting the scope of the invention,

y the claims appendedto this specification being relied upon for thatpurpose.

Figure 1 is a side elevationof a complete gage,

parts of the casing head being broken away to 4 v more clearly show itsconstruction. v

An object of the invention is to provide means Fig. 2 is a frontelevation of the complete gage;

the head thereof being shown in section to more clearly disclose thepivotally mounted contacting member, and

Fig. 3 shows the wiring diagram foran electric indicating instrumentwhich may be yused with the gage. .Y

In the above mentioned drawing I have shown but one embodiment of theinvention which is now deemed preferable, but it is to be understoodwithin the scope of the appended claims without departing from thespirit of the invention.

Briey and in its preferred aspect, my invention'may include thefollowing principal parts:

First, a base; second, a bracket supported thereon and adjustabledirectly toward and from the base;.third, a gage head member mounted onthe bracket for limited movement relative thereto in one direction only;fourth, a pivotally mounted contacting vmember within the head 'the axisof the pivot and normally to a line connecting thecontacts; sixth,electroemagneticcoils on opposite sides of the extended portion of thearm so that the end of the arm moves between the' coils as the positionof the gaging member changes; seventh, electric circuits andanindicating instrument associated with the coils and serving to indicatethe position of the arm between the coils and thus indicating thepositions of the contacts relative to the base.

'Referring more in detail to thefigures of the drawing, I provide a baseIII having a carefully finished plane surface dn its upper face on which-articles being compared may be. mounted. Ex-

tending from a portion of this -base III is an upf right post II uponwhich a bracket I2 may beA verticallyadjusted for movement directlytoward and from the base. For this purpose the bracket I2 is providedwith screws I3 which may beengaged with-the post to permit adjustment ofand locking of the bracket in any desired position.

Upon the free end of the bracket I2 is mounted a head member Il, vthismember ll'preferablyhav- `ing limited free movement relative to thebracket f in a direction directly toward' and from the base l iiexiblestrips of metal AI5 connect portions of the :,55` head I4 and bracket I2so that the head mem- III. For this purpose two parallelly disposed berI4 may move directly vertically relative to the bracket I2. By meansofthestrips 4I5 the head membera I4 maymove directly toward and 10 thatchanges and modifications may be made fromthe base I'I), that is, inl adirection normal to the surface of the base III on which articles W aremounted when being compared butl is restrained from moving in any otherdirection.

To limit; movements of the head I4 relative to the bracket I2 there areprovided overlapping lugs I6 outstanding respectively from the bracketand head. Preferably also a light spring II `mounted in the bracket mayengage a recess in zontal axis parallel to the surface of the base I0.On opposite sides of the axis of the pivots 2| and equi-distanttherefrom are contacts 22,

these preferably being in the form of lugs or studs outstanding from thelower surface of the tilting member 20. The direction of the pivotalaxis for this member is such that when blocks W of slightly varying sizeare placed on the base and under the contacts 22 the member 20 is tiltedto slightly udifferent positions.

vIn order to determine the position assumed by t e tilting member 20,which will therefore indicate the relative height of the two articles Wbeing compared, there is provided as an integral part of the member 20an upwardly extending arm 24 as shown most clearly in Fig. 2.

This arm 24 is symmetrical with respect to thev shorter arms on whichthe contacts 22 are mounted. The member 2II or at least'the extended endof the arm 24 is formed of -steel or other magnetic material. Onopposite `sides 'of this extended portion of the arm areelectro-magnetic- -coils 25. These coils 25 are suitably housed with--in metal cups, the position of .which toward or fromeach other may beslightly adjusted as by means of suitable screws 26.- Connected to thesecoils 25 is an indicating instrument 28 similar in every way to thatshown in my copending ap- Y' plication Serial No.A 3,led January 2,1935. Also provided in the electric circuit isla plate rectier 29 and a.suitable transformer 30. As the electric `circuits of this gage are'similar Ain every way to those shown and described in mycapendingapplication, it is vnot thought that an extended descriptionwill. be-necessary; it will suilice to state that different positions ofthe arm 24 between the coils 25 assumed by this arm 24 4when blocks Wofslightly diifering size are in engaging position will be indicated bythe varying positions of f the Vpointer ofthe indicating ment 28. y Y iNormally a light spring-3i forces the arm 24 in a direction so' that-theright hand contact 22 instruvaccesar as seen in Fig.v 2 will be at aless distance from the base than the left hand contact. Also vprovidedis an adjustable stop I2 adapted to limit the extreme position to whichthe ann. may be forcedby the 'spring II.

, Primarily this gage is designed for comparing' extremely accurateblocks with masters or standl ards of known precision.y By means of.this gage the standard and the specimen being compared therewith may besimultaneously mounted in f position.u The gage and blocks are thenallowed to come to standard temperature whereupon the indicator may beread andthe variation in size between the blocksy may be at oncedetermined.

The blocks may therefore be again compared in,

a similar manner in directly opposite `positions, ther blocks being'reversed so that they will be undei` the opposite contact. Anotherreading of the instrument is then taken. Variations of'- blocks frommasters or standards oi' known precision may. promptly be determined toan extreme precision.

What I claim is:

l. A linear gage comprising in combination, `a. base having a planespecimen supporting surface thereon, a gaging head adjustable towardvyand from said plane surface, a contacting member pivotally mountedwithin said head, said contacting. member having laterally spacedcontacts on opposite sides of its pivotal mounting whereby articles tobe gaged having opposite plane and parallel sgprfaces may individuallycontact therewith when 'mounted in position on said plane surface onsaid base, an arm on said con" tasting member` disposed symmetricallyrelative to said contacts, electro-magnetic coils on opposite sides ofsaid arm, and an electric instrument connected tosaid coils to determinethe position of said contacting member' and the contacts thereon when ingaging position.

2. A linear gage comprising in combination, a base having a planespecimen supporting surface. thereon, a gaging head adjustable towardand from said plane surface, a contacting member pivotally mountedwithin said head and supported for limited freemov'ement toward and fromsaid planesurface of said base, said contacting member having laterallyspaced contacts4 on opposite sidesjoffits pivotal mounting where byarticles to be gaged I iaving opposite plane and parallel surfaces mayindividually contact therewith when mounted in position on said plane.

surface on" said base, an arm on said contacting member` disposedsymmetrically relative tosa'il I- f contacts, electro-magnetic coils onopposite sides SPENCER B. may.'

